Refrigerating apparatus



Jan.'1,1935. A. A. KUCHER 1,985,931

I REFRIGERATING APPARATUS Filed March 16, 1932 2 'SheetS-Shet 1 Jan. 1 1935. A. A. KUCHER 7 1,935,931 I REFRIGERATI'NG APPARATUS Filed March 16, 1932 2 Sheets-Sheet 2 /[I114 7111711111. VIIIIII A IIIIIIIIIIIII VII/III III,

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Patented Jan. 1, 1935 REFBIGERATING APPARATUS Andrew A. Kucher, Dayton, Ohio, assignor to Fri:-

idaire Corporation, D

tion of Delaware ayton, Ohio, a corpora- Application March 16, 1932, Serial No. 599,238

18 Claims. (01. 62-126) The present invention relates to refrigerating apparatus. r

- Refrigerating systems generally consist of a compressor, condenser, expansion or pressure reducing device and an evaporator'and it is to the latter three named elements that my invention relates. When two sheet metal members are placed together to be welded I have found that the members do not contact each other throughout their entire surface due to irregularities in the thickness of the metal or to unevenness of the metal. Upon spot-welding such sheet metal members together at a plurality of predetermined spaced'apart points restricted passages or passages of capillary size are inherently formed, by the welding operation, between the sheet metal members adjacent the welded points. I therefore take advantage of this discovery in carrying out the objects hereinafter enumerated.

An object of my invention is to provide a simplified and improved element for use in re-. frigerating systems and in carrying out this object it is a more specific object to form a plurality of continuous inter-connected passages, of

capillary size or of small cross-sectional area. between superimposed sheet metal members, inherently by the act of welding the sheets together whereby the welded members provide an efilcient refrigerant expansion or pressure reducing device.

Another object of my invention is to weld certain corresponding portions of superimposed sheet metal members in one manner and to weld certain other portions thereof in another manner so as to provide a combined or unitary refrigerant pressure reducing and 'evaporting element for a refrigerated system.

It is a still further object of my invention to form the combined or unitary refrigerant pressure reducing and evaporating element, constructed according to the foregoing object, to

provide walls of a freezing zone vor enclosure adapted to receive ice trays or the like.

Further objects and advantages of the present invention will be apparent from the following description, reference being had'to the accompanying drawings, wherein a preferred form of the present invention is clearly shown.

Fig. 2 is an enlarged front view of the com- .bined refrigerant pressure reducing and evaporating element having the door thereof removed I and showing ice trays supported therein;

Fig. 3 is an elevational view of one side of the 5 combined refrigerant pressure reducing and evaporating element;

Fig. 4 is an elevational view of the side opposite that shown in Fig. 3 of the element;

Fig. 5 is an elevational view of one side of a 10 modified form of a combined refrigerant pressure reducing and evaporating element;

Fig. 6 is an elevational view of the opposite side of the modified form of element shown in Fig. 5;

Fig. '7 is a sectional view taken on the line 7-7 lb of Fig. 3 showing the restricted passage through the refrigerant pressure reducing portion of an element;

Fig. 8 is a sectional view through the refrigerant pressure reducing portion of an element-and 20 is taken on the line 8-8 of Fig. 3;

Fig. 9 is a sectional view similar to Fig. 8 showing a modified form;

Fig. 10 shows a refrigerant pressure reducing device constructed according to the present in- 25 vention and connected to a conventional evaporator;

Fig. 11 shows a sheet metal plate having raised portions formed therein; and

Fig. 12 shows the sheet metal plate folded upon 30 itself to form two thicknesses of metal adapted to bebent into a desired shape. 1

The desirability of present day manufacturers is to build various systems or apparatus as cheaply as possible while, at the same time, maintaining 35 eflicient operation and durability of the apparatus and it is to this end that my invention relates.

A further desirability is to eliminate from systems certain .elements which become worn or become a source of trouble and require adjustment 40 or repair. My invention particularly relates to the manufacture of elements used in refrigerating s'ystemsmith the foregoing desirabillties in mind and from the following description it will become apparent, that I have greatly reduced the 45 "cost of certain elements of such systems while at the same time insuring eflicient operation "and durability thereof.

Referring now to the drawings, for the' purpose of illustrating my invention, the numeral 15 designates arei'rlgerator cabinet having an insulated food storage compartment 16, closed by a doo'r'l'l',

a machine compartment 18, closed by adoor '19, provided therein. A cooling unit or evaporator 21 is disposed within the upper'portlon of compartt5 refrigerant flows from condenser 24 into a liquid refrigerant storage tank or receiver where it is stored prior to being circulated to the evaporator 21 through conduit 26. This liquid refrigerant may be admitted to the evaporator 21 by any controlled by any suitable means.

suitable ineans such as a pressure reducing or throttling device to be more fully described hereinafter. Refrigerant within the cooling unit or evaporator 21 upon absorbing heat from the medium, to be or' being cooled by the evaporator, vaporizes and is pumped back to the crankcase of compressor 22 through the conduit 2'7. Compressor 22 may be operated by any suitable means and I have shown an electric motor 28 opera- .tively connected with the compressor 22 through belt and pulley connections 29, 30, and 31 respectively. Operating periods of the motor 28 may be For example, I have shown a snap switch 33 comprising electric contacts 34 and 35 interposed in the electrical circuit leading'to motor 28. Switch 33 is actuated to make or break-the electric circuit to motor 28 by movement of a bellows 36 connected by pipe 3'7 to a thermostat bulb 38 responsive to the temperature of evaporator 21. The system just described is therefore cyclically operated in accordance with the temperature of evaporator 21.

In refrigerating systems of the type described,

it has been common to provide a valve mechanism having a valve therein movable with respect to its seat, in responw to a quantity of liquid refrigerant in the evaporator or to pressures existing in the system, to control the flow of refrigerant to the evaporator. My invention eliminates such movable valve mechanism. Since I have discovered that an eflicient refrigerant pressureor throttling device canbe constructed of sheet metal members and since refrigerant expansion or pressure reducing elements of all types become cold, due to refrigerant expanding therein and therefrom, it renders them suitable to be combined as a part of an evaporator. Therefore, I desire to incorporate such pressure reducing device in sheet metal members welded together and formed to provide anevaporator or cooling unit.

Referring again to the .drawings, I will first describe the method of making or forming a combined refrigerant pressure reducing and evaporating element. 1 have shown in Fig. 11 of the drawings a plate or sheet of thin gaugemetal 41 having a serpentine raised portion 42 formed therein.

One end 43 of the serpentine raised portion 42 is slightly larger in cross-sectional area than the main portion thereof and extends to the edge of sheet or plate 41. The opposite end 44 of the serpentine raised portion is spaced from the edge of sheet 41 and gradually diminishes in cross-sectional area into the flat portion of the plate. Directly opposite end 44 of the serpentine raised portion-42 there is a raised portion 45 extending a short distance inwardly from the edge of sheet 41 and has its inner portion gradually diminishing in cross-sectional area into the flat plate in a like manner to that of the end 44 of the S P 1- .tine raised portion. Obviously, the corresponding portions of plate or sheet 41 located between the raised portion 45 and the end 44 is in communication with the serpentine raised portion 42 and is flat or remains in its original form. After providing the foregoing raised portions in sheet or plate 41, this plate is bent upon itself along the line designated at AA in Fig. 11. The two superimposed sheet metalthicknesses orplates are then welded together in any'suitable manner around the edges of the serpentine raised portion 42 and the raised portion 45. This welding preferably extends only adjacent the dot-dash lines designated at B in Fig. 11 so as to permit the space between and surrounded by these dot-dash lines and the raised portions 44 and 45 to be free from welds of this first welding operation. Since the metal of the two layers of the sheet 41 within the area surrounded by the dot-dash lines 13 and raised portions 44 and 45 is not welded by the first welding operation, and since this portion of the double walled sheet is adapted to provide a refrigerant pressure reducing or throttling device, it is desirable to form restrictions therein so as to provide a plurality of continuous interconnected passages between the two thicknesses of metal. Such interconnected restricted passages should, of course, be in open communication with the raised portions 44 and 45 to form with the raised portions 42 and 43 a continuous passage having the portions 45 and 43 serving as an inlet and an outlet respectively for the passage. Therefore, in order to provide restrictions or passages of small area in cross-section between the plate members, formed by the single sheet of metal 41, I spot weld the members together at a'plurality of spaced apart adjacent points within the area defined by the dot-dash lines B. This spot welding operation thus provides a plurality of interconnected passages 46 (see Figs. '7 and 8) of substantially capillary size leading from the raised portion or inlet 45 to the open end 44 of the passage 42. After the foregoing operations have been performed upon the metal sheet 41, a plurality of right angle members 47 and 48 may be welded or secured to the double sheet metal plate as shown in Fig. 12. Couplings 50 and 50a are then secured between the two sheet metal members or plates at the raised portions 43 and 45 respectively and provide connections for the refrigerant conduits 26 and 27. The double walled metal sheet shown in Fig. 12 is then bent on a radius such as the radius defined at C in Fig. 12 to provide walls of a freezing zone or enclosure. This double walled sheet may be bent into any desired form and is preferably bent to form a U-shaped combined refrigerant pressure reducing and evaporating element. This U-shaped element can then be coated or plated with any suitable material, such as vitreous enamel, chrome, etc., to provide an easily cleaned evaporator of pleasing appearance. A back plate 49 and a pivoted front cover or door 51 may be placed on the element, in any suitable manner,

.plished with structures manifold passage has a plurality of vertical passages 55 leading therefrom and extending around the element to a horisontal discharge manifold passage 56. The manifold passage 56 is connected with the gaseous refrigerant outlet conduit 27 .'ofthesystem. -'1'hestructureshowninthel'igs.5

and 6 is illustrated to point out that my improved evaporator may comprise a plurality of refrigerant evaporating passages instead of a single passage extending therearound.

,1 have shown in m. o of the drawings a sec tionai view, similar-to the sectional viewyshown in Fig. 8, of a modified form of a combined refrigerant pressure reducing and evaporating element having a plurality of interconnected refrigerant evaporating passages. In this form of ele- 'ment, the pressure reducing portion may be formed therein as previously described and the refrigerant evaporating passage may be similar to the restricted passages of the pressure reducing device but of greater cross sectional area. In providing the refrigerant evaporating passages in this type of construction; the spot welds are spaced apart a predetermined distance according to the cross sectional area of the passage 42a de-' sired. These passages 42s are interconnected and are adapted to extend entirely around'the walls of the freezing enclosure.

In Fig. IO/of the drawings I have disclosed a refrigerant pressure reducing or throtting device 61 interposed between the liquid refrigerant supply conduit 26 and the coil or length of refrigerant evaporating pipe 42c having an outlet 43aconnected with the gaseous refrigerthe device 61 at the raised portions 444 and 45a,

in any suitable manner, for providing connections for the conduits 26, and 42c. The portion of the two plates or device 61 bounded by or within the dot-dash lines D is spot welded at a plurality of spaced apart points to provide inter-connected restricted passages of substantially capillary size or small in cross sectional area in the same manner as the passages 46 in the combined refrigerant pressure reducing and evaporating element previously described.

While I have shown the device 61 as being spot welded within the area defined by the dotdash lines D to-provide a plurality of interconnected passages of capillary size, I do not wish to be limited to this specific structure for the reason 'that the desired results may be accomdiflering only slightly from that shown by me. For instance, the spot welds within lines indicated at D may be' omitted. In such case an unobstructed restricted passage having an effective surface area wider in cross-sectional area than the inlet and outlet connections leadin: to and from. the restricted passage isprovided. I have found that-a structin'e' of the typ lust describedproducesthedesiredresultsequallyas well as the structure illustrated in the drawings,

but since I prefer to construct the device or the combined refrigerant pressure reducing and Y evaporating-element of thin gauge sheet metal it is preferable to spot weld the area within the the area defined by thedot-dash dot-dash lines D to insure against deformation is provided for a refrigerating system which eliminates the use of a movable valve commonly employed therein for controlling the flow of liquid refrigerant to the evaporator .of the system. It

is to be herein understood that by defining a refrigerant pressure reducing device or element 1'. mean that device or element of a refrigerating system which divides the system into low and high pressure portions and reduces the pressure of liquid refrigerant flowing from the high to the low pressure portion of the system at one point in the device to cause evaporation of the refrigerant. By defining a refrigerant evaporating element I mean that portion of the system which receives liquid refrigerant ata reduced pressure and permits evaporation or vaporization thereof in that portion of the system to abstract heat from a medium to be cooled by the evaporator. However, it will be appreciated that in a constructionor disclosure, wherein the cross sectional or surface area of all the passages combined of the pressure reducing device is greater than the cross sectional or surface area of the refrigerant inlet connection thereto, some evaporation or expansion of refrigerant occurs during its travel through the pressure reducing device and this device therefore becomes very cold, thereby rendering its incorporation with the evaporating por- I tion of a construction desirable to form a unitary For example, my combined or unitary refrigerant pressure reducing evaporator structure eliminates the use of an expansion device or valve separate from the evaporator and the novel construction of my refrigerant pressure reducing or throttling device eliminates the use of a valve mechanism containing a movable valve.

While the form of embodiment of the invention as herein disclosed, constitutes apreferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

l. A unitary refrigerant pressure reducing and evaporating element for arefrigerating apparatus comprising, two superimposed plates havin passages formed therebetween, said passages being connected and being of different cross-sectional area, the smaller passage providing the refrigerant pressure reducing portion of fthe element and the larger passage providing the refrigerant evaporating portion of the element.

2. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates, one of said plates having portions thereof spaced from the other of said platesto form passages between said plates, said passages being connected and being of different cross-sectional area, the smaller passage providing the refrigerant pressure reducing portion of the element and the larger passage providing the refrigerant evaporating portion of the element.

'3. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, two superimposed thin gauge sheet between, an inlet at one end of said passage and an outlet at the opposite end of said passage, said passage adjacent the inlet thereto being of small cross-sectional area and providing the refrigerant pressure reducing portion of the element, the portion of said passage extending from the small cross-sectional area thereof to said passage outlet being of greater cross-sectional area and providing the refrigerant evaporating portion of the element.

4. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates having a passage formed therebetween, an-inlet at one end of said passage and an outlet at the opposite end of said passage, said passage adjacent the inlet thereto having a plurality of restrictions formed therein providing the'refrigerant pressure reducing portion of the element, the portion of said passage extending from the restricted portion thereof to said passage outlet being of greater cross-sectional area than said restricted portion and providing the refrigerant evaporating portion of the element.

' 5. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates having a passage formed therebetween. an inlet at one end of said passage and an outlet at the opposite end of said passage,

said passage adjacent the inlet thereto, having a plurality of restrictions formed therein dividing the passage adjacent the inlet into a plurality of interconnected passages of, small cross-sectional area providing the refrigerant pressure reducing portion of the element, the portion of said passage extending from the plurality of restricted passages thereof to said passage outlet being of greater cross-sectional area and providing the refrigerant evaporating portion of the element.

6. A refrigerant pressure reducing device comprising superimposed sheet metal members having a plurality of continuous interconnected passages of substantially capillary size formed thereby and extending therebetween.

7. A refrigerant pressure reducing device comprising superimposed fiat sheet metal plates having a plurality of continuous interconnected passages of substantially capillary size formed thereby and extending therebetween.

8.. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, superimposed substantially smooth sheet metal members, said members having corresponding portions spot welded to ther at a plurality of adjacent points, said welds inherently forming a plurality of interconnected passages of small cross-sectional area forming the pressure reducing portion of the element, and said members having other corresponding portions formed to provide a passage of larger crosssectional area connected with said smaller passages and forming the evaporating portion of the element. ,v

9. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising. two superimposed thin gauge sheet metal plates, one of said plates having portions thereof spaced from the other of said plates to form a passage between said plates,'an inlet at one end of said passage and an outlet at the opposite end thereof, said passage adjacent the inlet thereto being of small cross-sectional area -1,9ss,es1. and providing. e refrigerant pressure reducingv portion of 'theelement, the portion ofsaid pas 1 sage extendingJrom the small cross-sectional 1 area thereof to said passage outlet being of greater cross-sectional area and providing the refrigerant evaporating portion of the element.

10. A unitary refrigerant pressure reducing and evaporating element for a refrigeratingapparatus comprising, two superimposed thin gauge sheet metal plates, one of said plates having portions thereof spaced from the other of said plates to form a passage between said plates, an inlet at one end of said passage and an outlet at the opposite end thereof, said passage adjacent the inlet thereto having a. plurality of restrictions formed therein providing the refrigerant pressure reducing portion of the element, the portion of said passage extending from the restricted portion thereof to said passage outlet being of greater cross-sectional area than said restricted portion and providing the refrigerant evaporating portion of the element.

11. A unitary refrigerant pressure reducing and evaporating element for a refrigerating apparatus comprising, two superimposed thin 1 gauge sheet metal plates, one of said plates having portions thereof spaced from the other of said plates to form a passage between said plates, an inlet at one end of said passage and an outlet at the opposite end thereof, said passage adjacent the inlet thereto having a plurality of restrictions formed therein dividing the passage adjacent the inlet into a plurality of interconnected passages of small cross-sectional area providing the refrigerant pressure reducing .portion of the element, the portion of said passageextending from saidpassages of small cross-sectional area to said passage outlet being of greater cross-sectional area and providing the refrigerant evaporating portion of the element.

12. An element for use in refrigerating apparatus comprising, superimposed substantially fiat sheet metal plates, said plates having corresponding portions spot welded together at a plurality of adjacent points, said welds inherently forming a plurality of continuous interconnected substantially capillary passages forming a pressure reducing device, and said plates having other corresponding portions formed to provide at least one larger passage connected with said capillary passages and forming an evaporating device substantially as described'and shown.

'13. A unitary refrigerant pressure reducing and evaporating element for refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates bent to form at least three walls of a freezing enclosure, said plates having passages formed therebetween, said es being connected and being ofdiiferent cross-sectional area, the smaller passage being confined within a small area of one of the walls of said enclosureand pro-' viding the refrigerant pressure reducing portion of the element and the larger e traversing substantially all the walls of said enclosure and providing the refrigerant evaporating portion of the element. 1

14. A unitary refrigerant pressure reducing and evaporating element for refrigerating apparatus 1 comprising, two superimposed thin gauge sheet metal plates bent to form substantially U-shaped walls defining a freezing zone, said plates having passages formed therebetween, one of said passages being confined within a small area'of a wall of said enclosure and having restrictions formed and traversing substantially all the walls of said.

enclosure and providing the refrigerant evaporating portionof the element.

15. A unitary refrigerant pressure reducing and-evaporating element for refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates bent to form atleast three walls of a freezing enclosure, one of said plates having portions thereof spaced from the other of said plates to form a passage between said plates,-

an inlet atone end of said passage and an outlet at the opposite end thereof, said passage adjacent the inlet thereto being of small cross-section- 'al area and providing the refrigerant pressure reducing portion of the element, the portion of said passage extending from the small cross-sectional area thereof to said passage outlet being of greater cross-sectional area and traversing substantially all the walls of said enclosure and providing the refrigerant evaporating portion of the element.

16. A unitary refrigerant pressure reducing and evaporating element for refrigerating apparatus comprising, two superimposed thin gauge sheet metal plates bent to form substantially U- shaped walls defining a freezing zone. one of said plates having portions thereof spaced from the other of said plates to form a passage between said plates, an inlet at one end of said passage and an outlet at the opposite end thereof, said passage adjacent the inlet thereto having re-' strictions formed therein and providing the refrigerant pressure reducing portion of the ele-,

ment, the portion. of said passage extending from the restricted portion thereof to said passage outlet being of greater cross-sectional area than said restricted portion and traversing substantially all the U -shaped walls and providing the refrigerant evaporating portion of the element.

17'. An element for use in refrigerating apparatus comprising superimposed sheet metal portions having, aplurality of continuous interconnected passages of substantially capillary size formed thereby and extending therebetween, said passages being formed solely by the operation of spot welding the sheet metal portions, together at a plurality ,of spaced apart points over their surf faces. 18. An element for use in refrigerating ap paratus' comprising superimposed substantially smooth flat sheet metal members having a plurality. of continuous interconnected restricted passages of substantially capillary size formed thereby and extending therebetween, said passages being formed solely by the operation of spot welding the sheet metal members together at a pluralityof spaced apart points over their surfates.- M

ANDREW A. KUCHER. 

